The present invention relates to a chemical analyzer or chemical analysis apparatus for analyzing components of a liquid of a living body, such as blood and/or urine, a water, etc., and in particular to the chemical analyzer being suitable for use of a so-called POC (Point-of-Care) testing, i.e., an urgent testing in an operation room or in a scene of urgency, a home or bed side testing, a quick testing beside a patient in a general medical clinic.
A chemical analyzer for the liquid of a living body, according to the conventional art, is disclosed and known, for example in U.S. Pat. No. 4,451,433. The apparatus is constructed with a calorimetric measurement portion for analyzing and/or determining the quantity of components, such as proteins and enzymes in blood and in urine, and an ion analyzing portion for analyzing ions in blood. This apparatus has a processing speed or velocity of performing several hundred tests per an hour, and a large-sized one has that more than 9,000 tests. In particular, in the system, for increasing up the processing speed in the calorimetric measurement portion, a large number of reactor vessels or cells are provided on a circumference of a turn table, upon an upper surface of the main body of the chemical analyzer, thereby to conduct mixing, reacting and measurement of blood samples, sequentially, through the overlapping processes thereof.
Main elements constructing such the apparatus are an automatic sample/reagent supply mechanism for supplying sample liquids and agents to the reactor vessels, a reservor portion for keeping containers of several-ten kinds of reagents therein, an automatic mixing mechanism for mixing the blood sample and the reagent in the reactor vessels, a measurement device for measuring properties of the blood samples which are under or have been completed with the reaction thereof, an automatic washing or rinsing mechanism for sucking and discharging the blood samples completed with the measurement thereof and for washing or rinsing the reactor vessels, an automatic washing or rinsing mechanism of the automatic sample/reagent supply mechanism for reducing mutual contamination between the blood samples due to deferring or carrying-over thereof and/or contamination between the different reagents, and a controller portion for controlling operations of those.
There are several-tens of kinds items of colorimetric measurements to be objected, and as the items in an ordinary test are, the analysis must be conducted on at least ten or more kinds of items for each one of the samples. For conducting the analysis of those items by means of only one apparatus, the reagent supply mechanism must be provided with a mechanism, such as a so-called reagent pipetting mechanism, with which the reagent is selected from a plurality of reagent containers to be supplied into the reactor vessels, sequentially, by a predetermined amount thereof. The reagent pipetting mechanism is constructed to mainly comprise a nozzle for sucking the reagent inside to hold it therein, a mechanism for moving the nozzle in a three-dimensional manner, and a suction/discharge control pump for sucking and/or discharging the reagent into and/or from the nozzle.
Also, as the conventional art, in particular for use in the POC testing, a blood analyzing apparatus is described in Japanese Patent Laying-Open No. Hei 9-504732 (1997) of PCT application No. PCT/US94/10299 (Publication No. WO95/06870). This analyzer comprised an optical detector, a main body of analyzer for performing control, signal processing, signal input/output, etc., and a disposable type of centrifugal reagent rotor portion(s) for performing adjustment for pre-processing with the reagent by introducing the sample liquid therein. First, the blood as the sample is injected into a guide or introduction opening which is provided at a central portion of a disc. After setting the rotor into the main body, the rotor is driven rotationally by an operation of the main body. In this instance, serum components are divided or separated from by means of the centrifugal function, so as to be determined in quantity by a predetermined amount of serum, and are mixed with a diluting liquid which is maintained inside the rotor. Further repeating stoppage and rotation of the rotor, the diluting liquid is introduced into the twelve (12) pieces of the reactor vessels which are provided around thereof. In each of the reactor vessels is already contained a dried reagent, which is corresponding to the respective different items of measurement, and also a ball for mixing, thereby mixing the reagent and the diluting liquid so as to start a predetermined reaction therebetween. After about twelve (12) minutes, an optical absorbance within the vessel is measured by the optical detector which is built-in within the main body. Those reagent rotors are prepared for several kinds thereof, corresponding to combinations of the items of measurement.
Requirements are made to such the analyzing apparatus for use in the POC testing, that it is small in sizes and portable, that the analysis results can be obtained quickly therefrom, that it is easy in handling thereof, that there is almost no necessity of maintenance for enabling or starting the analysis therewith at any time, and further that it is able to have a sufficient competitiveness in the cost, in particular, comparing to a testing by asking or requiring to a test center with charge, even in a case where it is used routinely for the testing nearby the patient, in a medical clinic or the like.
Therefore, there are problems listed below, in particular when applying the analyzing apparatus of the conventional arts mentioned above into the POC testing.
First, with the first conventional art, since the apparatus is large in the size, generally it is difficult to be provided or located, such as, in a scene of urgency or in an operation room where a space therein is limited or restricted. Also, since it is provided fixedly through conduits for the washing and disposal liquids, then it is impossible to be moved or carried nearby the patient staying at home and/or to bed side. Further, for using such the apparatus in the medical clinic and so on, a running cost, including the cost of the apparatus itself and the maintenance fee thereof is large, therefore the apparatus is not in economic.
Next, the chemical analyzer according to the second conventional art, it can be provided or located in such the operation room, etc., since it is small in the size, comparing to the large-sized chemical analyzer according to the first conventional art. Also, all the portions through which the sample liquid conducts with are made disposable, therefore there is no need of supplying the washing liquid to the conduits. Accordingly, the apparatus is relatively easy to be carried or moved and is preferable from a view point of maintenance thereof. And, it also has a feature that the cost of the apparatus itself is low. By the way, in the reagent rotor is contained the reagent(s) in advance, for use in measurement of the items which are made or determined by a maker thereof, therefore, there occur actually many cases where the measurement is made also on the unnecessary item(s) therein at the same time. Accordingly as will be mentioned in the following, there are problems in aspects of the quickness and the cost thereof, in particular relating to the POC testing.
First of all, even when there is a combination of the items required to be measured depending upon the condition of the patient in an urgent test, the analysis must be conducted sequentially by changing the several reagent rotors alternatively, if no reagent for such the combination is contained in that reagent rotor, as a result of this, it takes an excessive time. This comes to be a big problem in the urgent testing where the test result is required to be outputted quickly.
Second, since the items in analysis are already determined fixedly, the analysis is conducted even on the item which is inherently unnecessary to be analyzed, and the reagent rotor, which was used once for another measurement, must be disposed, even in a case where the unnecessary analysis must not be conducted. Therefore, it costs excessively, and is economically inferior in competitiveness of the cost, comparing to the testing by requiring to the test center mentioned above. At the present time, where a further suppression in the testing cost comes to be a very important factor due to reduction of medical expense, the above becomes a bottleneck for spreading the use of such the chemical analyzer widely, such as at home, bedside, in the medical clinics, etc.